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P. A. JUERGENS. METHOD OF AND MACHINE FOR MAKING SHEET METAL TUBES.

No. 523,073. Patented July 17, 1894.

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Patent-e F. A. JUERGENS. METHOD or AND MACHINE FOR MAKING SHEET METALTUBES.

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' I. A. JUERG'ENS. METHOD OF AND MACHINE FOR MAKING SHEET METAL TUBES.No. 523,073.

Patented July 17, 1894.

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UNITED STATES PATENT OFFICE.

FREDERICK A. JUERGENS, OF BUFFALO, NEW YORK, ASSIGNOR TO THE NIAGARASTAMPING AND TOOL COMPANY, OF SAME PLACE.

METHOD OF AND MACHINE FOR MAKING SHEET-METAL TUBES.

SPECIFICATION forming part of Letters Patent No. 523,073, dated July 17,1894;.

Application filed March 16,1894. Serial No. 503,850- (N'o model.)

To aZZ whom it may concern:

Be it known that I, FREDERICK A. J UER- GENS, a citizen of the UnitedStates, residing at the city of Buffalo, county of Erie, and State ofNew York, have inventeda new and useful Improvement in Methods of andMachines for Making Sheet-Metal Tubes, of which the following is aspecification.

This invention relates to a method of and machine for making round tubesof sheet metal, and has the object to produce a machine wherebypractically perfect tubes can be manufactured cheaply and expeditiously.

In the accompanying drawings consisting of three sheets: Figurel is aside elevation of a machine containing my invention and adapted forforming cylindrical tubes. Fig. 2 is a front elevation thereof. Figs.3,4, 5, 6 and 7 are fragmentary cross sections of the die, punch andconnecting parts, illustrating the principal operations informing acylindrical tube. Fig. 8 is an end View of a tube which has been partlyformed by slightly modified means. Fig. 9 is a vertical longitudinalsection of a machine embodying my invention and adapted to form tapertubes. Fig. 10 is a vertical cross section thereof in line 10-10, Fig.9. Fig. 11 is ahorizontalsection in line 1111, Fig. 9. Fig. 12 is a viewof a blank for making a taper tube.

Like letters of reference refer to like parts in the several figures.

The main frame of the machine for making cylindrical tubes, shown inFigs. 1 to 7, consists essentially of two side frames A A and a table Bconnecting the side frames. C represents a vertically movable cross headarranged above the table and guided with its ends in'ways c a formed inthe upper portions of the side frames. D represents a rock shaftjournaled in bearings d on the lower portions of the side frames andprovided at its center with a treadle d and at its ends with rock armsEE. The free ends of the latter are connected with the ends of the crosshead by connecting rods 6 e, whereby the movement of the treadle istransmitted to the cross head. The cross head is normallyheld in anelevated position by a spring F secured with its ends to the treadle andthe table. these parts may be constructed and combined in any ordinaryor suitable manner.

G represents the vertical back plate or back support of the die I,arranged upon the table and provided with a horizontal flange 9 which issecured to the table. on the table and secured to the front side of theback plate by bolts 1'.

H represents the punch which is secured to the under side of the crosshead by bolts h and moves contiguous to the vertical front face of theback plate. The face of the die is provided at its front end with agroove 2" which is adapted to receive a rib h, on the face of the punchfor effecting a primary bending of the front edge of the blank fromwhich the tube is to be formed. The faces of the primary. bending groove71' and rib h are curved and preferably approximate a quadrant.

J J are curling grooves formed respectively in the faces of the punchand die and whereby the body of the blank is curled into tubular form.These curling grooves are of semi-circular form, or nearly so, and arearranged in the rear of the primary bending groove and rib.

K represents .a holding groove which receives the rear or lower edge ofthe blank for holding the same in position preparatory to effecting thecurling operation. This holding groove is formed in the face of the diebetween the lower curling groove and the back plate and is equal inwidth to the thicknes of the blank.

The upper curling groove is arranged vertically in line with the lowercurling groove and its rear edge terminates flush with the All of Thedie I is arranged 7 face of the back plate, so that the punch upondescending will deflect the blank forwardly which has previously beenplaced against the face of the back plate.

L represents a guide or gage bar arranged in front of the die andprovided with aledge l on its rear side for supporting the rear edge ofthe blank during the primary bending of from the body portion of thetube.

its front end. The guide bar is secured with its ends, by bolts Z, toforwardly projecting arms 122 formed on the die.

N represents a removable mandrel which is placed inside of the curledtube for eifecting the finishing operation upon the tube.

The operation of forming a cylindrical tube is as follows: A rectangularsheet metal blank of the proper dimensions is placed with one edge uponthe ledge of the guidebar and with its opposite edge, which may becalled the front edge, in the bending groove or on the adjacent portionof the die. The punch is now lowered upon the die, whereby the frontedge of the blank is bent upwardly in a curve, as represented in Fig. 3.The punch is then raised and the blank is placed in an upright positionagainst the front side of the back support and with its edge into theholding groove of the die, so that the curved upper end of the blankprojects forwardly, as represented in Fig. 4. The punch is againlowcred, and during its descent the curling groove thereof engages withthe upper curved end of the blank and curls the latter into tubularform, as represented in Fig. 5. When the curling of the tube has beencompleted the rear or lower end of the blank, which is seated in theholding groove, projects tangentially In order to bend this tangentiallyprojecting ledge against the body of the tube, the cylindrical mandrelis next placed in the tube and the latter is turned in the curlinggroove of the die so that the projecting ledge of the blank is arrangeduppermost, as represented in Fig. 6. Upon again lowering the punch theprojecting ledge of the blank is pressed against the body of the tube,as shown in Fig. 7, thereby finishing the same. After the tube isfinished the mandrel is removed therefrom. The tubes so formed are roundand smooth, and this method and these devices permit the production oftubes which are very small in diameter, for instance speaking tubes andtubes which are used for inclosing electrical conductors, and they alsopermit the production of tube sections which are of great length.

If desired the primary bending of the front end of the blank may bedispensed with, in which case the front end of the blank tends toflatten upon curling the same, as shown at 0 in Fig. 8. This flattenedportion,however, is rounded upon inserting the mandrel in the tube andbending down the rear end of the blank during the finishing operation,illustrated in Figs. 6 and 7.

My invention is also applicable for forming taper tubes. A machinesuitable for this purpose is represented in Figs. 9 to 11. In thesefigures P represents a base provided with a vertical back plate 19. Qrepresents the die arranged upon the base adjacent to the back plate andprovided with a primary bending groove q, a lower curling groove q, anda holding groove g R represents a rock arm which is arranged in front ofthe back plate and pivoted upon one end of the base by a bolt 1'. Srepresents a punch secured to the underside of the rock arm and providedon its face with a primary bending rib s, and an upper curling grooveswhich are adapted respectively to co-operate with the primary bendingand curling grooves of the die. The punch is raised and lowered by meansof a rock lever T pivoted on the base and connected with the free end ofthe rock arm by a link 6. The sides of the grooves and rib of the punchand die converge longitudinally to a common point on the axis of therock arm, so as to cause the blank to curl properly into taper form, theoperations being the same as those described for making cylindricaltubes.

In making taper tubes the blank has the form of a segment, as shown' inFig. 12, and the mandrel is tapered to correspond with the form of thetube.

1 claim as my invention- 1. The herein described method of forming asheet metal tube from a fiat blank which consists in bending up thefront edge of the blank, then curling the blank between a punch and adie to give the blank an approximately round form and a projectingledge, then inserting a mandrel into the curled blank, and then closingthe projecting ledge against the tubular body of the blank,substantially as set forth.

2. The combination with a die provided with a curling groove and aholding groove arranged on one side of the curling groove and adapted toreceive the edge of the blank, of a punch provided with a curling groovearranged over the curling and holding grooves of the die, substantiallyas set forth.

3. The combination with the die, of aback support arranged in rear ofthe die and having a face adapted to support the blank, and a puncharranged to slide upon the face of the back support, substantially asset forth.

at. The combination, with a back support, of a die arranged in front ofsaid back support and provided with a curling groove and with a holdinggroove adjacent to said back support, and a punch arranged adjacent tothe back support and provided with a curling groove, substantially asset forth.

5. The combination with the die provided in its face at its front endwith a bending groove, a curling groove in rear of said bending groove,and a holding groove in rear of the curling groove, of a punch providedwith a curling groove, and a bending rib adapted, respectively, toco-operate with the curling and bending groove of the die, substantiallyas set forth.

G. The combination, with the back support having a vertical face on itsfront side, of a die provided in its face at its front end with abending groove, a. curling groove in rear of said bending groove, and aholding groove Witness my hand this 6th day of March, 1894.

FREDERICK A. JUERGENS.

Witnesses:

GEo. A. LAUTZ, THEO. L. POPP.

